(19)
(11) EP 0 242 935 B1

(12) EUROPEAN PATENT SPECIFICATION

(45) Mention of the grant of the patent:
04.09.1991 Bulletin 1991/36

(21) Application number: 87300297.6

(22) Date of filing: 14.01.1987
(51) International Patent Classification (IPC)5H04N 5/14, H04N 5/21

(54)

Video signal motion detecting apparatus

Videosignal-Bewegungsdetektor

Appareil détecteur de mouvement d'un signal vidéo


(84) Designated Contracting States:
AT DE ES FR GB IT

(30) Priority: 17.01.1986 US 819861

(43) Date of publication of application:
28.10.1987 Bulletin 1987/44

(73) Proprietor: RCA LICENSING CORPORATION
Princeton New Jersey 08540 (US)

(72) Inventors:
  • Weckenbrock, Hermann Johann
    Bordentown New Jersey (US)
  • Roeder, Barbara Joan
    Point Pleasant Pennsylvania (US)
  • Casey, Robert Francis
    Oradell New Jersey (US)
  • Harwood, Leopold Albert
    Bridgewater New Jersey (US)
  • Wedam, Werner Franz
    Lawrenceville New Jersey (US)

(74) Representative: Pratt, Richard Wilson et al
London Patent Operation G.E. Technical Services Co. Inc. Essex House 12/13 Essex Street
London WC2R 3AA
London WC2R 3AA (GB)


(56) References cited: : 
DE-A- 3 126 713
GB-A- 2 031 686
US-A- 4 352 126
GB-A- 2 015 294
GB-A- 2 045 574
US-A- 4 361 853
   
       
    Note: Within nine months from the publication of the mention of the grant of the European patent, any person may give notice to the European Patent Office of opposition to the European patent granted. Notice of opposition shall be filed in a written reasoned statement. It shall not be deemed to have been filed until the opposition fee has been paid. (Art. 99(1) European Patent Convention).


    Description


    [0001] This invention relates to apparatus for detecting time changes in images represented by video signals.

    [0002] Video signal processing circuitry such as field/frame comb filters, field/frame recursive filters or progressive scan generators for example, have been designed which significantly enhance the quality of images reproduced from video signals. These systems perform very well for images which contain no motion (either image object motion or camera panning). Conversely, when image motion does occur, such systems tend to introduce undesirable artifacts. Consequently, these memory based processing systems are designed to be motion adaptive, i.e. the systems are either altered or switched out of the signal processing path when image motion occurs.

    [0003] In order to alter motion adaptive systems during occurrences of image motion it is necessary to detect such occurrences. Typical motion detectors known in the art of video signal processing compare corresponding video signals from successive field or frame intervals. The assumption is made that if the interfield/frame video signals differ by more than a predetermined value motion has occurred.

    [0004] Because video signals emanate from varying sources, e.g. different broadcast stations, VCR's, they tend to have varying signal-to-noise ratios (SNR's). Differences in SNR's complicates designing motion detectors to discriminate between image motion and image noise. One approach to discriminating between noise and motion is to average a number of signal differences corresponding to pixels surrounding the picture point being examined. Noise being uncorrelated, will tend to cancel. Signal differences corresponding to image object motion for localized pixels tend to exhibit a degree of correlation and thus add constructively.

    [0005] The signal differences that are averaged are selected to correspond to pixels that are symmetrically disposed horizontally, vertically or both about the pixel being examined. Some systems weight the signal differences being averaged so that the signal averages exhibit a low-pass response.

    [0006] Motion detectors are known which examine field/frame differences to determine the occurrence of motion are designed to operate on component rather than composite video signals. The reason for this is that chrominance components of composite video signals do not have similar phase relationships from frame-to-frame. Inherent frame-to-frame chrominance differences will produce motion signals even for still images. In order to preclude false motion detection when successive frames of composite video signal are compared, the composite video signal is typically limited to the low frequency luminance spectrum before comparison.

    [0007] Examining only the low frequency spectrum of interframe composite video signal differences for motion, tends not to be satisfactory. In this instance motion of fine image detail cannot be detected. As an example, movement of a person's hair will not be detected in the reproduced image regardless of the speed of motion. Failure to detect motion of fine detail will generally tend to result in a blurred image.

    [0008] Motion detectors are known which do operate on composite video and a) separate the luminance and chrominance components, b) align the phase of the corresponding frame-to-frame chrominance components, c) recombine the phase altered chrominance component with the luminance component and d) take the interframe difference of the composite and chrominance phase altered composite video signals. This approach to detecting motion in composite video signals is not satisfactory because luminance and chrominance components cannot be completely separated in the chrominance spectrum of the composite video signal. The unseparated or residual luminance component in the separated chrominance signal undergoes an alteration during the chrominance phase alignment process. When this altered high frequency luminance is recombined and the interframe signal differences are taken, signal differences may occur in the absence of motion resulting in false motion detection.

    [0009] GB-A-2O45 574 discloses a video movement detection apparatus suitable for detecting picture movement and/or noise on a video signal. The apparatus comprises a first detector for detecting differences frame by frame on a portion of picture having a plurality of picture points from more than one line, a second detector for detecting differences frame by frame from a portion of picture having a plurality of picture points from the same line, and a third detector for detecting differences frame by frame from a portion of a picture comprising a single picture point. Movement is determined to have taken place when the differences measured by the respective detectors exceed predetermined thresholds. The selected thresholds are typically of different values to provide the capability of distinguishing between noise and movement in varying conditions.

    [0010] The present invention seeks to provide detection of motion in a video signal with a minimum of false detection signals due to noise and cross components.

    [0011] According to the present invention there is provided a signal interimage motion detector comprising:
       a signal interimage motion detector comprising an input terminal (CV) for receiving a video signal; and means coupled to said input terminal for providing differences between video signals from successive image periods; characterized by first means, coupled to said means for providing differences, for summing a plurality of said differences, said plurality of differences including a difference corresponding to an image point currently under examination for interimage motion, and differences corresponding to image points proximate said image point under examination occurring in a horizontal image line containing said image point under examination and in a preceding horizontal image line to produce first summed differences; second means, coupled to said means for providing differences, for summing a plurality of said differences, said plurality of differences including a difference corresponding to said image point under examination, and differences corresponding to image points proximate said image point under examination occurring in said horizontal image line containing said image point under examination and in a succeeding horizontal image line to produce second summed differences; and means coupled to said first and second summing means, for producing a motion signal whenever said first and second summed differences concurrently exceed a predetermined magnitude value.

    [0012] For a better understanding of the present invention, reference will now be made, by way of example, to the accompanying drawings, in which:-

    FIGURE 1 is a block diagram of a motion detector including apparatus to detect motion in composite video signal.

    FIGURE 2 is a partial block, partial schematic diagram of a detector for detecting motion represented by interimage changes in the luminance component of composite video signals.

    FIGURE 3 is a chart of composite signal samples corresponding to portions of two frames of video information and the sample differences between the two frames of information.

    FIGURE 4 is a partial block, partial schematic diagram of an embodiment of the FIGURE 2 motion detector shown in greater detail.

    FIGURE 5 is a block diagram of a detector for detecting motion represented by interimage changes in the chrominance component of composite video signals and FIGURE 6 is a more detailed schematic diagram of one embodiment of the detector illustrated in FIGURE 5.



    [0013] In the following description the assumption is made that the composite video signal applied to the motion detecting apparatus is in sampled data format. For purposes of illustration, the sample rate is selected to be four times the color subcarrier rate and phase locked to color burst, though other sample rates may be selected. In the diagrams, the elements are illustrated in functional terms which are applicable to both analog and digital signal processing environments since the invention may be practiced with either analog or digital circuits. All of the individual circuit elements, both digital and analog, are well known in the art of video signal processing, and, thus, will not be described in detail. Depending on the choice of processing circuitry it may be necessary to include compensating signal delay elements to align in time signals in the different circuit paths, but one skilled in the art of circuit design will readily comprehend and include such delays.

    [0014] Referring to FIGURE 1, composite video (CV) signal which may be supplied from a television tuner in a TV receiver environment, from a color camera, or from the signal pickup circuitry in a VCR environment etc. is applied to delay element 10, a luminance motion detector 12 and a chrominance motion detector 14. Delayed signal from delay element 10 is coupled to respective second input connections of detectors 12 and 14. For NTSC composite video signals, delay element 10 will typically delay the applied signal CV by precisely one frame interval. For PAL composite video signal delay element 10 may delay the signal CV by two frame intervals.

    [0015] Luminance motion detector 12 compares the current and delayed video luminance component of the composite video signals and generates a motion signal (LM) if a predetermined difference exits between the two luminance signals. Chrominance motion detector 14 compares the current and delayed chrominance components of the composite video signals and generates a motion signal (CM) if a predetermined difference exists between the two chrominance signals. The motion signals LM and CM from detectors 12 and 14 are coupled to respective inputs of an OR gate 16 which develops a motion signal when either the luminance or chrominance motion detectors generate a motion signal.

    [0016] FIGURE 2 illustrates one embodiment of a luminance signal motion detector which may be implemented as motion detector 12 in FIGURE 1. In FIGURE 2 the current and delayed composite video signals are coupled to respective input terminals of the subtracter 20. Subtracter 20 develops frame difference samples which are coupled to the input terminals of a low-pass filter 22 and a high-pass filter 24. Low-pass filter 22 passes that portion of the composite video signal frequency spectrum not normally occupied by the chrominance component. Conversely, high-pass filter 24 (which may be a bandpass filter) passes that portion of the composite video signal spectrum which is normally occupied by the chrominance component.

    [0017] The signal differences provided by low-pass filter 22 are coupled to a signal combining element 26. Combining element 26 sums a number of the frame difference samples. Element 26 is drawn as a matrix of three rows with three squares in each row. Each of the squares represents a signal difference sample. The central square corresponds to the image point or sample under examination for image motion. The square to the left and right of the central box correspond to sample differences occurring on the same horizontal image line. However, it is to be understood that these two sample differences need not correspond to the immediately preceding and succeeding sample differences in the stream of sample differences occurring at the four-times color subcarrier rate. The squares in the rows above and below the middle row correspond to sample differences from horizontal image lines occurring before and after the image line containing the pixel under examination. The cross hatching is intended to illustrate that each of the sample differences represented by the squares in the illustrative 3x3 matrix contribute to the sum generated by combining element 26.

    [0018] The sum produced by element 26 is applied to a threshold detector 28. Threshold detector 28 provides a logic one output signal for the condition that the sum exceeds a predetermined magnitude and a logic zero otherwise. A digital embodiment of the threshold detector 28 may comprise the cascade connection of an absolute value circuit and an N-input OR gate. The absolute value circuit is configured to convert all sums to a single polarity signal. If the output signal of the absolute value circuit is a parallel N-bit signal, the M more significant bits are coupled to the M more significant input connection of the N-input OR gate. The N-M lesser significant bit connections of the OR gate are coupled to a logic zero signal. In such a configuration the OR gate will develop a logic one output signal for sums having magnitudes exceeding the values (2N-M-1).

    [0019] The output signal of the threshold detector 28 is coupled to one input connection of the two-input OR gate 40.

    [0020] The output signal from the high-pass filter 24 is coupled to two signal combining circuits 30 and 34. Combining circuit 30 combines sample differences from the horizontal image line containing the pixel under examination and a horizontal image line preceding the image line containing the pixel under examination. The central square in the illustrative matrix corresponds to the pixel under examination. The cross hatching indicates the samples that are combined by element 30. The samples that are combined from the two lines are vertically aligned relative to the displayed image. The preceding line is selected such that the vertically aligned samples have an antiphase color subcarrier relationship. For example, if the composite video signal is an NTSC signal the preceding line is the immediately preceding image line, or the third, fifth, etc. most immediate preceding line. The difference samples to the right and left of the difference sample corresponding to the pixel under examination need not be the difference samples immediately preceding and following the control difference sample.

    [0021] The output of the combining element 30 is coupled to a threshold detector 32 which develops a logic one output signal for the condition that the combined difference samples exceed a predetermined magnitude and a logic zero otherwise. The output signal from threshold detector 32 is coupled to one input connection of a two input AND gate 38.

    [0022] Combining element 34 is similar to combining element 30 except that it combines sample differences from the horizontal image line containing the difference sample corresponding to the pixel under examination with difference samples from a horizontal image line occurring later in time. The combined difference samples from combining element 34 are coupled to a threshold detector 36 which functions similarly to threshold detector 32. The output signal from threshold detector 36 is coupled to a second input connection of the AND gate 38.

    [0023] AND gate 38 produces a logic one output signal only when both threshold detectors 32 and 36 concurrently produce logic one output signals. The output signal from AND gate 38 is coupled to a second input connection of OR gate 40. OR gate 40 produces a logic one output signal, indicating image motion, whenever threshold detector 28 or AND gate 38 output logic one signals.

    [0024] In the FIGURE 2 arrangement, elements 22, 26 and 28 detect image motion represented by luminance signal defining coarse image object detail. Elements 24, 30-38 detect image motion represented by luminance signal defining fine image object detail. For fine detail motion detection, parallel combining-circuit-threshold-detection circuits are incorporated to preclude false motion detection resulting from particular image chrominance transitions as will be explained with reference to FIGURE 3.

    [0025] The threshold values selected for threshold detectors 28, 32 and 36 may be fixed constants or made variable as a function of signal-to-noise ratio (SNR) as is known in the art of e.g. video signal recursive filters. Typically threshold detectors 32 and 36 will be designed to respond to like threshold values. Threshold detector 28 in general will require a dissimilar threshold value because a) combining element 26 combines a larger number of difference samples than elements 30 and 34, and b) the difference samples combined by element 26 contains less cross components than the difference samples combined by elements 30 and 34.

    [0026] Shown in FIGURE 3 are corresponding samples from portions of three successive horizontal image lines of two successive frames of NTSC composite video. The samples occur in conformance to a four times subcarrier sampling rate phase locked to the subcarrier. Yij values correspond to the luminance component. The ±Iij and ±Qij values correspond to quadrature related chrominance components wherein the ± signs designate sampling phase and not necessarily sample polarity. In general successive I values along a horizontal line have substantially equal magnitude and are of opposite polarity. Similarly successive Q values have substantially equal magnitudes and are of opposite polarity. Due to the relatively high redundancy of video signal information vertically aligned samples from line-to-line represent like picture information.

    [0027] The frame-to-frame sample differences, as developed by e.g. subtracter 20 in FIGURE 2 are also illustrated. The ΔYij terms represent the luminance differences and the ±(Iij+I′ij) and ±(Qij+Q′ij) terms represent chrominance sample differences. In FIGURE 2 the low-pass filter 22 attenuates the ±(Iij+I′ij) and ±(Qij+Q′ij) terms so that combining circuit only operates on lower frequency ΔYij luminance differences. If no image changes occur between frames, the values ΔYij will be zero except for noise contributions, i.e. electrical noise or quantization noise. Due to the random nature of noise, summing a number of the ΔYij terms as in combining element 26 will tend to average the noise contribution to zero. Thresholding the sums in detector 28 is performed to add a further degree of noise immunity. Disregarding noise, if interframe image changes occur, a number of the ΔYij samples will be non zero. This is so even for slight image changes because the signal is over sampled. Thus, summing a number of ΔYij values in the vicinity of the pixel under examination will produce a larger motion signal than examining a single pixel difference sample. The SNR of the motion signal is therefore significantly enhanced.

    [0028] The sample differences applied to combining elements 30 and 34 contain both high frequency luminance differences and chrominance information. Note that for NTSC signals, frame-to-frame chrominance components are antiphasal. Subtracting the interframe chrominance components has the effect of summing them as indicated in the matrix of difference sample values.

    [0029] Due to the relatively high line-to-line redundancy of video images, and to the line-to-line antiphasal relationship of the chrominance component, summing vertically aligned difference samples from two adjacent lines will tend to cancel the chrominance components of the difference samples, leaving the high frequency luminance differences ΔYij.

    [0030] Combining element 30 sums the difference samples from e.g. lines l and 2 shown in FIGURE 3, and combining element 34 sums the difference samples from e.g. lines 2 and 3 shown in FIGURE 3.

    [0031] If the pixel under examination corresponds to a difference sample in line 2 either the sum from combining element 30 or 34 may indicate high frequency luminance motion. The parallel detectors (30-32) and (34-36) are incorporated to preclude false motion detection. Images occur wherein from line-to-line there may be a chrominance transition from one color to a different color or a transition from a colored image to a black and white image. For either of these conditions summing the line-to-line difference samples will not cancel the chrominance component resulting in a false detection. However, it is extremely unlikely that such a condition will concurrently occur between both the pair of lines 1 and 2 and the pair of lines 2 and 3. Therefore, if one, but not both, of detectors (30-32) and (34-36) generate a motion signal, one of these special image conditions, and not motion, is the cause. To preclude false detection, the two detectors are ANDED together. In effect detector (30-32) in conjunction with the AND gate 38 monitors detector (34-36) for such false motion detection and vice versa.

    [0032] The effect of chrominance transitions causing false detection may be reduced further by judicious selection and weighting of the difference samples combined in elements 30 and 34. Let the difference samples be designated Sij where the indices correspond to the indices of the ΔYij components in FIGURE 3. Further, let the difference sample S₂₃ correspond to the pixel under examination. A combining element 30 which combines samples S₁₁, S₂₁, S₁₅, S₂₅ in a ratio of 1:2 with samples S₁₃ and S₂₃ will be significantly less sensitive to vertical chrominance transitions because the weighting tends to structure the combining circuitry to perform notch filtering at the chrominance subcarrier frequency. Combining element 34 will be similarly designed to sum the difference samples S₂₁, S₃₁, S₂₅, S₃₅ in the ratio of 1:2 with the difference samples S₂₃ and S₃₃.

    [0033] FIGURE 4 shows circuitry for realizing this latter embodiment. In FIGURE 4 the low-pass filtered difference samples from filter 22 are coupled to two cascade connected delay elements 52 and 54 and to one input connection of a sample summing circuit 56. Delay elements 52 and 54 each provide a like delay interval of an integral number of sample periods e.g. one, two or three sample periods. Delayed difference samples from delay elements 52 and 54 are coupled to respective second and third input connections of summing circuit 56. Summing circuit 56 produces difference sample sums, S, of three difference samples from the same horizontal image line, which may be described by the equation






    [0034] The difference sample sums from summing circuit 56 are coupled to the cascade connection of two one-horizontal-line delay elements 58 and 60. The output signals from summing circuit 56, delay element 58 and delay element 60 are coupled to respective input connections of summing circuit 62 and represent sample sums from three horizontal image lines. Summing circuit 62 produces a difference sample sum of three difference samples from each of three successive lines. This sample sum is coupled to the threshold detector 64 which corresponds to the threshold detector 28 in FIGURE 2. The output signal from threshold detector 64 corresponds to a low frequency luminance motion signal and is coupled to an input connection of OR gate 86.

    [0035] The difference samples from the subtracter 20 are coupled to the minuend input connection of subtracter 50 and the low-pass filtered difference samples from filter 22 are coupled to the subtrahend input connection of subtracter 50. The frequency spectrum exhibited by the signal output from subtracter 50 is complementary to the signal spectrum of the signal output from the low-pass filter 22. In other words the combination of subtracter 50 and low-pass filter 22 forms a high-pass filter with respect to the composite video signal spectrum.

    [0036] High-pass filtered difference samples from subtracter 50 are coupled to the cascade connection of the two delay elements 66 and 68. In this particular embodiment delay elements 66 and 68 each provide signal delays of two sample periods. In consequence, delay elements 68 and 66 and the input of delay element 66, provide every second sample difference i.e. Si1, Si3 and Si5. The output connection of subtracter 50, delay element 66 and delay element 68 are coupled to respective input connections of weighting and combining circuit 70. The outer difference samples Si1 and Si5 are weighted by one-half and summed with the difference sample Si3, to form the weighted sum of three sample differences from one horizontal image line.

    [0037] The weighted sums from weighting and combining circuit 70 are coupled to the cascade connection of the two one-horizontal-line delay elements 72 and 74. The input and output connections of delay element 72 are coupled to respective input connections of adder 76. Adder 76 produces difference sample sums which correspond to the sums produced by combining element 30 in FIGURE 2. The input and output connections of delay element 74 are coupled to respective input connections of a further adder 78. Adder 78 produces difference sample sums corresponding to the output sums provided by combining element 34 of FIGURE 2.

    [0038] The output sums provided by adders 76 and 78 are coupled to threshold detectors 80 and 82 respectively. The output connections of threshold detectors 80 and 82 are coupled to respective input connections of the two-input AND gate 84, the output of which is coupled to the second input connection of OR gate 86.

    [0039] In the circuitry of FIGURES 2 and 4 the full band signal differences may be applied directly to the high frequency detectors, i.e. (30-32) and (34-36), and the low frequency detector (26-28) omitted. The advantage of this arrangement is a reduction in hardware. The disadvantage is a small penalty in terms of motion/noise discrimination because the low frequency detector (26-28) exhibits a better motion/noise ratio due to the symmetry of differences selected.

    [0040] FIGURE 5 illustrates a detector for detecting inter-image motion represented by the chrominance component of composite video signal and which may be used for the motion detector 14 in FIGURE 1. In FIGURE 5, current composite video signal samples and corresponding frame delayed composite video samples are coupled to respective input connections of an adder 90. If there are no inter-image changes, adder 90 will produce sample sums corresponding to 2Yij. The chrominance components being antiphase from frame-to-frame cancel in the summing process. Conversely, if there is inter-image motion the sums output by adder 90 will correspond to 2Yij+ΔYij±ΔIij or to 2Yij+ΔYij±ΔQij, where ΔYij is the image change represented by the luminance component and ±ΔIij and ±ΔQij are image changes represented by the quadrature related chrominance components. The chrominance changes ΔIij and ΔQij alternate in polarity at the subcarrier rate and thus are designated ±ΔI and ±ΔQ. The changes ΔIij and ΔQij will tend substantially to be antiphasal from line-to-line (NTSC) and antiphasal every two lines for PAL signals.

    [0041] The sample sums produced by adder 90 are applied to a filter 92 which attenuates samples having frequencies outside the band of frequencies normally occupied by the chrominance component of composite video signal. The filtered sample sums are coupled to sample combining circuits 94 and 96.

    [0042] Combining element 94 combines sample sums from the horizontal image line containing the sample sum representing the current pixel under examination and sample sums from a previously occurring horizontal image line. Combining element 96 combines sample sums from the horizontal image line containing the sample sum, representing the pixel under examination and sample sums from a succeeding horizontal image line. All of the sample sums combined by either element 94 or 96 are in relatively close proximity to the sample sum representing the pixel under examination though not necessarily immediately adjacent. Combining elements 94 and 96 are represented by like matrixes of three rows of three squares per row.

    [0043] Each row represents a portion of sample sums from one image line. Each square represents a sample sum. However, only the sample sums represented by a square containing a plus or a minus sign are included in combined samples produced by combining elements 94 and 96. In addition, the plus and minus signs designate the polarity with which each of the sample sums are combined. The sample sums of each vertically aligned pair of sums are combined with opposite polarity. Because of the high line-to-line redundancy of most images the luminance components in the vertically aligned sample sums will cancel. The polarity selection by which the sample sums are combined also tend to render the chrominance component differences to a single like polarity so that all non zero chrominance differences sum constructively to produce a motion signal with enhanced SNR.

    [0044] The combined sample sums generated by combining circuits 94 and 96 are applied to respective threshold circuits 98 and 100. Threshold circuits 98 and 100 develop logic one output signals if the signal applied to its respective input connection exceeds a predetermined value and develop logic zeroes otherwise. The output connection of threshold circuits 98 and 100 are coupled to respective input connections of the two-input AND gate 102. AND gate 102 produces a logic one output signal, indicating image motion, only when both of the threshold circuits 98 and 100 concurrently produce logic one output signals.

    [0045] The chrominance motion detector utilizes parallel detectors (94,98) and (96,100) to preclude false motion detection resulting from line-to-line or vertical luminance transitions which would defeat luminance cancellation in either one or the other of the combining circuits. It is very unlikely that such a luminance transition will occur between the two lines from which samples are combined by circuit 94 and concurrently between the two lines from which samples are combined by circuit 96. Thus, for line-to-line luminance transitions not due to image motion, only one of the detectors (94,98) or (96,100) will develop a motion signal, which is insufficient to condition AND gate 102 to produce a chrominance motion signal. However, it is certain that if motion occurs at pixels represented by the squares in the middle row of sample sums, which row contains the pixel under examination, both detectors 94 and 96 will simultaneously detect such occurrence. In this instance AND gate 102 will be conditioned to provide a chrominance motion signal.

    [0046] FIGURE 6 shows one embodiment of the FIGURE 5 motion detector in greater detail. In FIGURE 6, elements designated with like numerals to those in FIGURE 5 perform like functions.

    [0047] In FIGURE 6 the high-pass filtered sample sums from filter 92 are coupled to the cascade connection of two similar delay elements 110 and 112. Delay elements 110 and 112 each delay the sample sums by a small number of sample periods. It is advantageous that delay elements 110 and 112 be designed to delay samples by two sample periods to ensure more complete luminance cancellation. This result arises by virtue of including only one of the quadrature chrominance components (e.g. the ΔIij component) in the combined sample sums.

    [0048] The sample sums from the filter 92 and the twice delayed sample sums from delay element 112 are coupled to non-inverting input connections of the summing circuit 114. The delayed sample sums from delay element 110 are coupled to an inverting input connection of summing circuit 114. Circuit 114 develops the sum of the sample sums applied to its non-inverting input connections and the negative of the sample sums applied to its inverting input connection, which sums correspond to the sums of sample sums along one horizontal image line. Note that the inverting and non-inverting inputs may be interchanged without altering the system function. In addition, more than three sample sums per horizontal line may be combined. Finally, the sample sums may be weighted as in the FIGURE 4 circuitry.

    [0049] The combined sums from the summing circuit 114 are coupled to the cascade connection of two one-horizontal-line delay elements 116 and 118. Delayed combined sums occurring at the output connections of delay element 118 correspond to the combination of sample sums from the top row of squares in the matrix of elements 94 and 96 in FIGURE 5. The output connections of delay element 116 provides combined sums corresponding to the combination of sample sums represented by the middle row of squares in the matrix of elements 94 and 96 in FIGURE 5, and the output connection of combining element 114 provides combined sums corresponding to the combination of sample sums represented by the bottom row of squares in the matrix elements 94 and 96.

    [0050] The combined sums from the output connections of delay elements 116 and 118 are applied to the subtrahend and minuend input connections of subtracter 122 respectively. Substracter 122 combines the combined sums in accordance with the respective sample sum polarities indicated in the matrix of element 94. The output of subtracter 122 is threshold detected in threshold circuit 98, the output of which in coupled to one input connection of AND gate 102.

    [0051] The combined sum from the output connections of combining element 114 and delay element 116 are coupled to the minuend and subtrahend input connections respectively of subtracter 120. Subtracter 120 combines the combined sums in accordance with the respective sample sum polarities indicated in the matrix of element 96 of FIGURE 5. The combined sums produced by subtracter 120 are threshold detected in threshold circuit 100, the output of which is coupled to a second input connection of AND gate 102. AND gate 102 develops a chrominance motion, signal on the condition that the combined sums from subtracters 120 and 122 concurrently exceed a predetermined threshold value.

    [0052] In the foregoing embodiments the circuitry initially combines sample sums occurring in respective horizontal lines and then combines the combined samples from the respective horizontal lines. It will be appreciated by those skilled in the art of signal processing that sample sums from the different horizontal lines may be combined first, and then these combined sums combined horizontally. A further alternative embodiment may provide all of the sample sums and/or difference signals of the respective matrices simultaneously, which samples may then be combined in a tree arrangement of adders/subtractors.

    [0053] The illustrative embodiments imply that the motion indicating output signals are single bit bilevel signals. It will be appreciated by those skilled in the art that the motion indicating signals may be multi-bit signals which may correspond, for example, to the average of the combined samples produced by the respective combining means, or the differences between the combined samples and the appropriate threshold values etc.


    Claims

    1. A signal interimage motion detector comprising:
       an input terminal (CV) for receiving a video signal; and
       means (10,20) coupled to said input terminal for providing differences between video signals from successive image periods;
       characterized by first means (30), coupled to said means for providing differences, for summing a plurality of said differences, said plurality of differences including a difference corresponding to an image point currently under examination for interimage motion, and differences corresponding to image points proximate said image point under examination occurring in a horizontal image line containing said image point under examination and in a preceding horizontal image line to produce first summed differences;
       second means (34), coupled to said means for providing differences, for summing a plurality of said differences, said plurality of differences including a difference corresponding to said image point under examination, and differences corresponding to image points proximate said image point under examination occurring in said horizontal image line containing said image point under examination and in a succeeding horizontal image line to produce second summed differences; and
       means (32,36,38), coupled to said first and second summing means, for producing a motion signal whenever said first and second summed differences concurrently exceed a predetermined magnitude value.
     
    2. A detector according to claim 1 for detecting interimage motion in images represented by a composite video signal wherein:
       the input terminal (CV) is for receiving the composite video signal (CV);
       the providing means (10,20) comprises delay means (10), coupled to said input terminal, for providing replicas of said composite video signal delayed by an integral number, including one, of image periods and means (20) coupled to said input terminal and said delay means for providing differences of said composite video signal and said delayed composite video signal;
       and further comprising means (24), including means coupled to said providing means (20), for passing to a first output terminal differences having frequency components normally occupied by chrominance components of said composite video signal to the relative exclusion of other frequency components of said composite video signal;
       and wherein the said first and second means (30,34) are coupled to said first output terminal;
       and the motion signal producing means comprises a first threshold detector (32), coupled to said first means, for producing a motion indicating signal when summed differences applied thereto exceed a predetermined magnitude
       a second threshold detector (36), coupled to said second means, for producing a motion indicating signal when summed differences applied thereto exceed a predetermined magnitude, and
       means (38,84), coupled to said first and second threshold detectors for providing, at a second output terminal, a motion indicating signal whenever the first and second threshold detectors concurrently produce motion indicating signals.
     
    3. A detector according to Claim 2 which, further includes:
       means (22), coupled to said means (20) for providing differences, for passing to a third output terminal, differences having frequency components of said composite video signal not normally occurring in the frequency spectrum occupied by said chrominance component;
       third means (26,56,62), coupled to said third output terminal, for summing a plurality of said differences, said plurality of differences corresponding to image points symmetrically disposed about said image point under examination;
       a third threshold detector (28,64), coupled to said third means, for producing a motion indicating signal when summed differences applied thereto exceed a predetermined magnitude; and
       means (40,86) coupled to said third threshold detector and said second output terminal for providing at a fourth output terminal a motion indicating signal whenever said third threshold detector or said second output terminal produce a motion indicating signal.
     
    4. A detector according to Claim 3 wherein said differences occur as sampled data differences and said third means (26) comprises:
       a cascade connection of
       means (56) for summing a plurality of sample differences corresponding to image points occurring in one horizontal image line and
       means (62) for summing summed sample differences corresponding to image points occurring in successive horizontal image lines.
     
    5. A detector according to any one of claims 2 to 4 wherein said differences occur as sampled data differences and said first means (30) includes:
       first summing means (70) coupled to said first output terminal for summing difference samples corresponding to image points occurring in the same horizontal image line; and
       second summing means (78) coupled to said first summing means, for summing summed difference samples provided by said first summing means from two different horizontal image lines; and
       wherein said second means (34) includes means (76) coupled to said first summing means (70), for summing summed difference samples provided by said first summing means from two horizontal image lines one of which is different from the horizontal image lines summed by said second summing means.
     
    6. A detector according to any one of claims 2 to 5 further comprising:
       means (90) coupled to said input terminal and said delay means (10) for providing sums of said composite video signal and said delayed composite video signal;
       filter means (92), coupled to said means (90) for providing sums, for passing frequency components of said sums normally occurring in the frequency band of composite video signal occupied by chrominance components;
       first additional means (94,114,122), coupled to said filter means (92) for summing a plurality, even in number, of said sums, said plurality of sums corresponding to image points occurring in a horizontal line containing said image point under examination and image points occurring in a horizontal image line preceding said horizontal image line containing said image point under examination, said first additional means (94,114,122) summing alternate sums along a horizontal image line in opposite polarity and wherein one half of said plurality of sums are in a positive polarity sense and one half of said plurality of sums are in a negative polarity sense;
       a first additional threshold detector (98), coupled to said first additional means (94,114,122), for producing a motion indicating signal whenever summed signals provided by said first combining means exceed a predetermined magnitude;
       second additional means (96,114,120), coupled to said filter means (92), for summing a plurality, even in number, of said sums, said plurality of sums corresponding to image points occurring in said horizontal line containing said image point under examination and image points occurring in a horizontal image line following said horizontal image line containing said image point under examination, said second additional means (96,114,120) summing alternate sums along a horizontal image line in opposite polarity and wherein one half of said plurality of sums are summed in a positive polarity sense and one half of said polarity sum are summed in a negative polarity sense;
       a second additional threshold detector (100), coupled to said second additional means (96,114,120), for producing a motion indicating signal whenever summed signals provided by said second additional means exceed a predetermined magnitude;
       means (102) coupled to said first additional and second additional threshold detectors for providing a chrominance motion indicating signal when said first additional and second additional threshold detectors concurrently provide motion indicating signals.
     
    7. A detector according to Claim 6 which further includes means (16) responsive to said chrominance motion indicating signal and said motion indicating signal provided by said second output terminal for providing a motion indicating signal on the occurrence of said chrominance motion indicating signal or said motion indicating signal provided at said second output terminal.
     
    8. A detector according to Claim 6 or Claim 7 wherein said sums occur as sampled data sums and said first additional means (94) includes:
       a cascade connection of first and second delay elements (110,112) coupled to said filter (92) for providing delayed replicas of said sums, said first and second delay elements each providing like delays of an integral number of sample periods;
       means (114) coupled to said filter (92) and said second delay element (112) for summing said sum samples from said filter and twice delayed sum samples rrom said second delay element in opposite polarity sense with once delayed sum samples from said first delay element (110) to produce horizontally summed sum samples;
       a further delay means (118) coupled to said means (114) for producing horizontally summed sum samples, said further delay means (118) providing sample delays of one horizontal image line period; and
       a further means (122) coupled to an input and an output of said further delay means (118) for summing said horizontally summed sum samples in opposite polarity.
     
    9. A detector according to any one of Claims 6 to 8 in which said preceding horizontal image line is selected such that chrominance components therein have an antiphase relationship with chrominance components corresponding to said horizontal image line containing said image point under examination.
     
    10. A detector according to claim 1 for detecting composite signal interimage motion, wherein the input terminal is for receiving the composite video signal (CV);
       the providing means (20,24) provides said differences as interimage difference samples, of corresponding signals from two image periods, from frequency components of said composite video signal containing fine luminance image detail information;
       and the motion signal producing means (32,36,38) is coupled to said first and second combining means, for producing a fine detail luminance motion signal whenever said first and second summed difference samples concurrently exceed a predetermined magnitude value.
     
    11. detector according to Claim 10 further comprising
       means (20,22) coupled to said input terminal for producing interimage difference samples from frequency components of said composite video signal representing coarse luminance image detail information;
       a third means (26) for summing a plurality of difference samples representing coarse luminance detail information to produce third summed difference samples, said plurality of difference samples representing coarse luminance detail information corresponding to image points proximate said image point under examination; and
       means (28) coupled to said third means, for producing a coarse detail luminance motion indicating signal whenever said third summed difference samples exceed a predetermined magnitude.
     
    12. A detector according to Claim 11 further comprising means (40) responsive to said fine detail luminance motion indicating signal and said coarse detail luminance motion indicating signal for developing a luminance motion indicating signal whenever either of said fine or coarse detail luminance motion indicating signals indicate motion.
     
    13. A detector according to any one of claims 10 to 12 further comprising
       means (90,92) coupled to said input terminal for producing interimage sample sums of corresponding signals from two image periods, from frequency components of said composite video signal containing chrominance components
    to the substantial exclusion of other frequency components of composite video signal;
       first means (94) coupled to the means for producing sample sums, for combining a plurality of sample sums selected from sample sums corresponding to image points occurring in said horizontal image line containing said image point under examination and a preceding horizontal image line, wherein alternate sample sums from a horizontal image line are combined in opposite polarity sense and one half of said plurality of sample sums are combined in a positive polarity sense and one half in a negative polarity sense to produce first combined samples sums;
       second means (96) coupled to the means for producing sample sums for combining a plurality of sample sums selected from sample sums corresponding to image points occurring in said horizontal image line containing said image point under examination and a succeeding horizontal image line, wherein alternate sample sums from a horizontal image line are combined in opposite polarity sense and one half of said plurality of sample sums are combined in a positive polarity sense and one half in a negative polarity sense to produce a second combined samples sums; and
       means (98,100,102) coupled to said first and second means for combining sample sums, for producing a chrominance motion indicating signal whenever said first and second combined sample sums concurrently exceed a predeteremined magnitude.
     
    14. A detector according to Claim 13 further comprising means (16) responsive to said chrominance motion indicating signal and said fine detail luminance motion signal for producing an image motion indicating signal whenever either said chrominance or luminance motion signals indicate motion.
     


    Revendications

    1. Un détecteur de mouvement interimages d'un signal comprenant :
       une borne d'entrée (CV) pour recevoir un signal vidéo ; et
       un moyen (10, 20) couplé à la borne d'entrée pour produire des différences entre les signaux vidéo de périodes d'images successives;
       caractérisé par une premier moyen (30), couplé audit moyen produisant des différences, pour additionner un certain nombre desdites différences, ce certain nombre de différences comprenant une différence correspondant à un point d'image actuellement sous examen pour mouvement interimages et des différences correspondant à des points d'image à proximité du point d'image sous examen se produisant dans une ligne d'image horizontale contenant ledit point d'image sous examen et dans une ligne d'image horizontale précédente pour produire des premières différences additionnées ;
       un second moyen (34), couplé audit moyen pour produire des différences, pour additionner un certain nombre desdites différences, ledit certain nombre de différences comprenant une différence correspondant à un point d'image sous examen, et des différences correspondant à des points d'image à proximité du point d'image sous examen se produisant dans la ligne d'image horizontale contenant ledit point d'image sous examen et dans une ligne d'image horizontale successive pour produire des secondes différences additionnées ; et
       un moyen (32, 36, 38), couplé aux premier et second moyens d'addition, pour produire un signal de mouvement chaque fois que des premières différences additionnées excèdent concurremment une valeur de grandeur prédéterminée.
     
    2. Un détecteur selon la revendication 1 pour détecter un mouvement interimages dans des images représentées par un signal vidéo composé où :
       la borne d'entrée (CV) est destinée à recevoir le signal vidéo composé (CV) ;
       le moyen de production (10, 20) comprend un moyen à retard (10), couplé à la borne d'entrée, pour produire des reproductions du signal vidéo composé retardé par un nombre entier, comprenant un, de périodes d'image et un moyen (20) couplé à la borne d'entrée et au moyen à retard pour produire des différences du signal vidéo composé et du signal vidéo composé retardé ;
       et comprenant de plus un moyen (24), comprenant un moyen couplé au moyen de production (20) , pour laisser passer à une première borne de sortie des différences ayant des composantes de fréquence normalement occupées par des composantes de chrominance du signal vidéo composé à l'exclusion relative d'autres composantes de fréquence du signal vidéo composé ;
       et où des premier et second moyens (30, 34) sont couplés à la première borne de sortie ;
       et le moyen de production de signal de mouvement comprend un premier détecteur de seuil (32), couplé au premier moyen, pour produire un signal d'indication de mouvement lorsque des différences additionnées appliquées à celui-ci excèdent une grandeur prédéterminée,
       un second détecteur de seuil (36), couplé au second moyen pour produire un signal d'indication de mouvement lorsque des différences additionnées appliquées à celui-ci excèdent une grandeur prédéterminée, et
       un moyen (38, 84), couplé aux premier et second détecteurs de seuil pour produire à une seconde borne de sortie, un signal d'indication de mouvement chaque fois que les premier et second détecteurs de seuil produisent concurremment des signaux d'indication de mouvement.
     
    3. Un détecteur selon la revendication 2 qui comprend de plus :
       un moyen (22) , couplé au moyen précité (20) pour produire des différences, pour laisser passer à une troisième borne de sortie des différences ayant des composantes de fréquence du signal vidéo composé ne se produisant pas normalement dans le spectre de fréquences occupé par la composante de chrominance précitée ;
       un troisième moyen (26, 56 62), couplé à la troisième borne de sortie, pour additionner un certain nombre desdites différences, le certain nombre des différences correspondant à des points d'image disposés symétriquement au point d'image précité sous examen ;
       un troisième détecteur de seuil (28, 64), couplé au troisième moyen pour produire un signal d'indication de mouvement lorsque des différences additionnées appliquées à celui-ci excèdent une grandeur prédéterminée ; et
       un moyen (40, 86) couplé au troisième détecteur de seuil et à la seconde borne de sortie pour produire à une quatrième borne de sortie un signal d'indication de mouvement chaque fois que le troisième détecteur de seuil ou la seconde borne de sortie produit un signal d'indication de mouvement.

     
    4. Un détecteur selon la revendication 3 où les différences précitées se produisent comme différences de données échantillonnées et le troisième moyen précité (26) comprend :
       une connexion en cascade
       d'un moyen (56) pour additonner un certain nombre de différences d'échantillons correspondant aux points d'image se produisant dans une ligne d'image horizontale et
       d'un moyen (62) pour additionner les différences d'échantillons additionnées correspondant aux points d'image se produisent dans des lignes d'images horizontales successives.
     
    5. Un détecteur selon l'une des revendications 2 à 4 où les différences précitées se produisent comme différences de données échantillonnées et le premier moyen précité (30) comprend :
       un premier moyen d'addition (70) couplé à la première borne de sortie précitée pour additionner des échantillons de différence correspondant à des points d'image se produisant dans la même ligne d'images horizontale ; et
       un second moyen d'addition (78) couplé au premier d'addition, pour additionner des échantillons de différences additionnées produites par le premier moyen d'addition à partir de deux lignes d'images horizontales différentes ; et
       où le second moyen précité (34) comprend un moyen (76) couplé au premier moyen d'addition (70) pour additionner des échantillons de différences additionnées produits par le premier moyen d'addition à partir de deux lignes d'images horizontales dont l'une est différente des lignes d'images horizontales additionnées par le second moyen d'addition.
     
    6. Un détecteur selon l'une des revendications 2 à 5 comprenant de plus :
       un moyen (90) couplé à la première borne d'entrée précitée et au moyen à retard précité (10) pour produire des sommes du signal vidéo composé et du signal vidéo composé retardé précités ;
       un moyen de filtrage (92), couplé au moyen (90) pour produire des sommes pour laisser passer les composantes de fréquence desdites sommes se produisant normalement dans la bande de fréquences du signal vidéo composé occupée par les composantes de chrominance ;
       un premier moyen additionnel (94, 114, 122), couplé au moyen de filtrage (92) pour additionner un certain nombre, pair en nombre desdites sommes, le certain nombre de sommes correspondant aux points d'image se produisant dans une ligne horizontale contenant le point d'image sous examen et des points d'image se produisant dans une ligne d'image horizontale précédant la ligne d'image horizontale contenant le point d'image sous examen, le premier moyen additionnel (94, 114, 122) additionnant des sommes alternées le long d'une ligne d'image horizontale de polarité opposée et où une moitié dudit certain nombre de sommes a un sens de polarité positif et une moitié dudit certain nombre de sommes a un sens de polarité négative ;
       un premier détecteur de seuil additionnel (98), couplé au premier moyen additionnel (94, 114, 122) pour produire un signal d'indication de mouvement chaque fois que des signaux additionnés produits par le premier moyen de combinaison excèdent une grandeur prédéterminée;
       un second moyen additionnel (96, 114, 120), couplé au moyen de filtrage (92), pour additionner un certain nombre pair en nombre, desdites sommes, ledit certain nombre de sommes correspondant à des points d'image se produisant dans une ligne horizontale contenant le point d'image sous examen et des points d'image se produisant dans une ligne d'image horizontale suivant la ligne d'image horizontale contenant le point d'image sous examen, le second moyen additionnel (96, 114, 120) additionnant des sommes alternées le long d'une ligne d'image horizontale de polarité opposée et où une moitié dudit certain nombre de sommes est additionnée dans un sens de polarité positive et une moitié de la somme des polarités est additionnée dans un sens de polarité négative ;
       un second détecteur de seuil additionnel (100), couplé au second moyen additionnel (96, 114, 120) pour produire un signal d'indication de mouvement chaque fois que des signaux additionnés produits par le second moyen additionnel excèdent une grandeur prédéterminée ;
       un moyen (102) couplé aux premier et second détecteurs de seuil additionnels pour produire un signal d'indication de mouvement de chrominance lorsque les premier et second détecteurs de seuil additionnels produisent concurremment des signaux d'indication de mouvement.
     
    7. Un détecteur selon la revendication 6 qui comprend de plus un moyen (16) répondant au signal d'indication de mouvement de chrominance précité et au signal d'indication de mouvement précité produits par la seconde borne de sortie précitée pour produire un signal d'indication de mouvement à l'apparition du signal d'indication de mouvement de chrominance ou du signal d'indication de mouvement produit à la seconde borne de sortie.
     
    8. Un détecteur selon la revendication 6 ou la revendication 7 où les sommes précitées se produisent comme sommes de données échantillonnées et le premier moyen additionnel (94) précité comprend :
       une connexion en cascade de premier et second éléments à retard (110, 112) couplée au filtre précité (92) pour produire des reproductions retardées desdites sommes les premier et second éléments à retard produisant chacun des retards identiques d'un nombre entier de périodes d'échantillon ;
       un moyen (114) couplé au filtre (92) et au second élément à retard (112) pour additionner des échantillons de somme dudit filtre et retarder de deux fois des échantillons de somme du second élément à retard de sens de polarité opposé avec des échantillons de somme retardés une fois du premier élément à retard (110) pour produire des échantillons de somme additionnés horizontalement ;
       un autre moyen à retard (118) couplé au moyen (114) pour produire des échantillons de somme additionnés horizontalement, ledit autre moyen à retard (118) produisant des retards d'échantillon d'une période de ligne d'image horizontale ; et
       un autre moyen (122) couplé à une entrée et une sortie de l'autre moyen à retard (118) pour additionner lesdits échantillons de somme additionnés horizontalement de polarité opposée.
     
    9. Un détecteur selon l'une des revendications 6 à 8 dans lequel la ligne d'image horizontale précédente précitée est choisie de telle sorte que les composantes de chrominance dans celle-ci ont une relation en opposition de phase avec les composantes de chrominance correspondant à la ligne d'image horizontale précitée contenant le point d'image précité sous examen.
     
    10. Un détecteur selon la revendication 1 pour détecter un déplacement interimages du signal composé, où la borne d'entrée est destinée à recevoir le signal vidéo composé (CV) ;
       le moyen de production (20, 24) produit les différences précitée comme échantillons de différence interimages de signaux correspondants à partir de deux périodes d'images des composantes de fréquence du signal vidéo composé contenant l'information de détail d'image de luminance fin ;
       et le moyen de production du signal de mouvement (32, 36, 38) est couplé aux premier et second moyens de combinaison précités pour produire un signal de mouvement de luminance de détail fin chaque fois que les premier et second échantillons de différence à additionner excèdent concurremment une valeur de grandeur prédéterminée.
     
    11. Un détecteur selon la revendication 10 comprenant de plus
       un moyen (20, 22) couplé à la borne d'entrée précitée pour produire des échantillons de différences inter images à partir des composantes de fréquence du signal vidéo composé représentant l'information de détail d'image de luminance grossier ;
       un troisième moyen (26) pour additionner un certain nombre d'échantillons de différence représentant l'information de détail de luminance grossier pour produire des troisièmes échantillons de différence additionnés, ledit certain nombre d'échantillons de différence représentant une information de détail de luminance grossier correspondant à des points d'image à proximité du point d'image précité sous examen ; et
       un moyen (28) couplé au troisième moyen pour produire un signal d'indication de mouvement de luminance de détail grossier chaque fois que les troisièmes échantillons de différence additionnés dépassent une grandeur prédéterminée.
     
    12. Un détecteur selon la revendication 11 comprenant de plus un moyen (40) répondant au signal d'indication de mouvement de luminance de détail fin et au signal d'indication de mouvement de luminance de détail grossier pour produire un signal d'indication de mouvement de luminance chaque fois que soit le signal d'indication de mouvement de luminance de détail fin, soit le signal d'indication de mouvement de luminance de détail grossier indique un mouvement.
     
    13. Un détecteur selon l'une des revendications 10 à 12 comprenant de plus
       un moyen (90, 92) couplé à la borne d'entrée précitée pour produire des sommes d'échantillons interimages des signaux correspondants à partir de deux périodes d'images à partir de composantes de fréquence du signal vidéo composé contenant des composantes de chrominance à l'exclusion substantielle d'autres composantes de fréquence du signal vidéo composé ;
       un premier moyen (94) couplé au moyen pour produire les sommes d'échantillons pour combiner un certain nombre des sommes d'échantillons choisies à partir des sommes d'échantillons correspondant aux points d'image se produisant dans la ligne d'image horizontale précitée contenant le point d'image précité sous examen et une ligne d'image horizontale précédente où des sommes d'échantillons alternés d'une ligne d'image horizontale sont combinées en sens de polarités opposés et une moitié dudit certain nombre de sommes d'échantillons est combinée dans un sens de polarité positive et une moitié dans un sens de polarité négative pour produire des premières sommes d'échantillons combinées ; et
       un second moyen (96) couplé au moyen pour produire des sommes d'échantillons pour combiner un certain nombre de sommes d'échantillons choisies à partir des sommes d'échantillons correspondant aux points d'image se produisant dans la ligne d'image horizontale contenant le point d'image sous examen et une ligne d'image horizontale suivante où des sommes d'échantillons alternées d'une ligne d'image horizontale sont combinées en sens de polarités opposés et une moitié dudit certain nombre de sommes d'échantillons est combinée dans un sens de polarité positive et une moitié dans un sens de polarité négative pour produire des secondes sommes d'échantillons combinées ; et
       un moyen (98, 100, 102) couplé aux premier et second moyens pour combiner des sommes d'échantillons pour produire un signal d'indication de mouvement de chrominance chaque lois que les première et seconde sommes d'échantillons combinées excèdent concurremment une grandeur prédéterminée.
     
    14. Un détecteur selon la revendication 13 comprenant de plus un moyen (16) répondant au signal d'indication de mouvement de chrominance et au signal de mouvement de luminance de détail fin pour produire un signal d'indication de mouvement d'image chaque fois que le signal de mouvement de chrominance ou de luminance indique un mouvement.
     


    Ansprüche

    1. Detektor für Bewegungen von Bild zu Bild in einem Signal,
       mit einer Eingangsklemme (CV) zum Empfang eines Videosignals
       und mit einer mit der Eingangsklemme gekoppelten Einrichtung (10, 20) zur Bildung von Differenzen zwischen Videosignalen aus aufeinanderfolgenden Bildperioden,
       gekennzeichnet durch:
       eine mit der Einrichtung zur Bildung von Differenzen gekoppelte Einrichtung (30) zur Summierung einer Mehrzahl der Differenzen, wobei diese Mehrzahl eine Differenz enthält, die einem Bildpunkt zugeordnet ist, der gerade auf Bewegung von Bild zu Bild geprüft wird, und Differenzen, die Bildpunken zugeordnet sind, welche sich in der Nähe des unter Prüfung stehenden Bildpunktes befinden und in einer den unter Prüfung stehenden Bildunkt enthaltenden horizontalen Bildzeile und in einer vorangehenden horizontalen Bildzeile liegen, um erste summierte Differenzen zu erzeugen;
       eine mit der Einrichtung zur Bildung von Differenzen gekoppelte zweite Einrichtung (34) zur Summierung einer Mehrzahl der Differenzen, wobei diese Mehrzahl eine Differenz enthält, die dem unter Prüfung stehenden Bildpunkt zugeordnet ist, und Differenzen, die Bildpunkten zugeordnet sind, welche sich in der Nähe des unter Prüfung stehenden Bildpunktes befinden und in der den unter Prüfung stehenden Bildplunkt enthaltenden horizontalen Bildzeile und in einer nachfolgenden horizontalen Bildzeile liegen, um zweite summierte Differenzen zu erzeugen, und
       eine mit der ersten und der zweiten summierenden Einrichtung gekoppelte Einrichtung (32, 36, 38) zur Erzeugung eines Bewegungssignals immer dann, wenn die ersten und die zweiten summierten Differenzen gleichzeitig einen vorbestimmten Betragswert überschreiten.
     
    2. Detektor nach Anspruch 1 zur Erfassung von Bild-zu-Bild-Bewegung in Bildern, die durch ein Videosignalgemisch dargestellt werden, wobei:
       die Eingangsklemme (CV) zum Empfang des Videosignalgemischs (CV) vorgesehen ist;
       die differenzbildende Einrichtung (10, 20) eine mit der Eingangsklemme gekoppelte Verzögerungseinrichtung (10) aufweist, um Nachbildungen des Videosignalgemischs zu liefern, die um eine ganze Zahl, einschließlich eins, von Bildperioden verzögert sind, und eine mit der Eingangsklemme der Verzögerungseinrichtung gekoppelte Einrichtung (20) zur Bildung von Differenzen zwischen dem Videosignalgemisch und dem verzögerten Videosignalgemisch; ferner eine Einrichtung (24) vorgesehen ist, die mit der differenzbildenden Einrichtung (20) gekoppelt ist, um an einer ersten Ausgangsklemme Differenzen mit Frequenzkomponenten durchzulassen, die normalerweise von Farbartkomponenten des Videosignalgemischs belegt werden, unter relativem Ausschluß anderer Frequenzkomponenten des Videosignalgemischs,
       und wobei die besagte erste und zweite Einrichtung (30, 34) mit der besagten ersten Ausgangsklemme gekoppelt sind
       und die das Bewegungssignal erzeugende Einrichtung folgendes aufweist: einen ersten Schwellendetektor (32), der mit der ersten Einrichtung gekoppelt ist, um ein bewegungsanzeigendes Signal zu erzeugen, wenn ihm angelegte summierte Differenzen einen vorbestimmten Betrag überschreiten,
       einen zweiten Schwellendetektor (36), der mit der zweiten Einrichtung gekoppelt ist, um ein bewegungsanzeigendes Signal zu erzeugen, wenn ihm angelegte summierte Differenzen einen vorbestimmten Betrag übersteigen, und    eine Einrichtung (38, 84), die mit dem ersten und dem zweiten Schwellendetektor gekoppelt ist, um an einer zweiten Ausgangsklemme ein bewegungsanzeigendes Signal immer dann zu erzeugen, wenn der erste und der zweite Schwellendetektor gleichzeitig bewegungsanzeigende Signale erzeugen.
     
    3. Detektor nach Anspruch 2, der ferner folgendes enthält:
       eine Einrichtung (22), die mit der differenzbildenden Einrichtung (20) gekoppelt ist, um an einer dritten Ausgangsklemme Differenzen durchzulassen, welche Frequenzkomponenten des Videosignalgemischs enthalten, die normalerweise nicht in dem von der Farbartkomponente belegten Frequenzspektrum vorkommen;
       eine dritte Einrichtung (26, 56, 62), die mit der dritten Ausgangsklemme gekoppelt ist, um eine Mehrzahl der Differenzen zu summieren, wobei diese Mehrzahl Bildpunkten zugeordnet ist, die symmetrisch bezüglich des unter Prüfung stehenden Bildpunktes liegen;
       einen dritten Schwellendetektor (28, 64), der mit der dritten Einrichtung gekoppelt ist, um ein bewegungsanzeigendes Signal zu erzeugen, wenn ihm angelegte summierte Differenzen einen vorbestimmten Betrag übersteigen, und
       eine Einrichtung (40, 86), die mit dem dritten Schwellendetektor und mit der zweiten Ausgangsklemme gekoppelt ist, um an einer vierten Ausgangsklemme ein bewegungsanzeigendes Signal immer dann zu erzeugen, wenn der dritte Schwellendetektor oder die zweite Ausgangsklemme ein bewegungsanzeigendes Signal liefert.
     
    4. Detektor nach Anspruch 3, wobei die Differenzen als Differenzen von Datenabtastwerten erscheinen und die dritte Einrichtung (26) folgendes aufweist:
       eine Kaskadenschaltung aus
       einer Einrichtung (56) zur Summierung einer Mehrzahl von Abtastwert-Differenzen, die Bildpunkten zugeordnet sind, welche in ein und derselben horizontalen Bildzeile liegen, und
       eine Einrichtung (62) zur Summierung summierter Abtastwert-Differenzen, die Bildpunkten zugeordnet sind, die in aufeinanderfolgenden horizontalen Bildzeilen liegen.
     
    5. Detektor nach einem der Ansprüche 2 bis 4, wobei die Differenzen als Differenzen von Datenabtastwerten erscheinen und die erste Einrichtung (30) folgendes enthält:
       eine mit der ersten Ausgangsklemme gekoppelte erste Summierungseinrichtung (70) zur Summierung von Differenz-Abtastwerten, die Bildpunkten entsprechen, welche in ein und derselben horizontalen Bildzeile liegen, und
       eine mit der ersten Summierungseinrichtung gekoppelte zweite Summierungseinrichtung (78) zur Summierung summierter Differenz-Abtastwerte, die von der ersten Summierungseinrichtung aus zwei verschiedenen horizontalen Bildzeilen geliefert werden, und
       wobei die zweite Einrichtung (34) eine mit der ersten Summierungseinrichtung (70) gekoppelte Einrichtung (76) enthält, um summierte Differenz-Abtastwerte zu summieren, die von der ersten Summierungseinrichtung aus zwei horizontalen Bildzeilen geliefert werden, von denen eine eine andere als diejenigen horizontalen Bildzeilen ist, die von der zweiten Summierungseinrichtung summiert werden.
     
    6. Detektor nach einem der Ansprüche 2 bis 5, ferner enthaltend:
       eine Einrichtung (90), die mit der Eingangsklemme und mit der Verzögerungseinrichtung (10) gekoppelt ist, um Summen des Videosignalgemischs und des verzögerten Videosignalgemischs zu bilden;
       eine Filtereinrichtung (92), die mit der summenbildenden Einrichtung (90) gekoppelt ist, um solche Frequenzkomponenten der Summen durchzulassen, die normalerweise in dem von Farbartkomponenten belegten Frequenzband des Videosignalgemischs vorkommen;
       eine erste zusätzliche Einrichtung (94, 114, 122), die mit der Filtereinrichtung (92) gekoppelt ist, um eine geradzahlige Mehrzahl der Summen durchzulassen, wobei diese Mehrzahl der Summen Bildpunkten zugeordnet ist, welche in einer den unter Prüfung stehenden Bildpunkt enthaltenden Horizontalzeile vorkommen, und Bildpunkte, welche in einer horizontalen Bildzeile vorkommen, die der den unter Prüfung stehenden Bildunkt enthaltenden horizontalen Bildzeile vorangehen, wobei die erste zusätzliche Einrichtung (94, 114, 122) abwechselnde Summen entlang einer horizontalen Bildzeile in entgegengesetzter Polarität miteinander addiert und wobei eine Hälfte der besagten Mehrzahl von Summen einen positiven Polaritätssinn und eine Hälfte der Mehrzahl von Summen einen negativen Polaritätssinn hat;
       einen ersten zusätzlichen Schwellendetektor (98), der mit der ersten zusätzlichen Einrichtung (94, 114, 122) gekoppelt ist, um ein bewegungsanzeigendes Signal immer dann zu erzeugen, wenn summierte Signale, die von der ersten Kombiniereinrichtung geliefert werden, einen vorbestimmten Betrag übersteigen;
       eine zweite zusätzliche Einrichtung (96, 114, 120), die mit der Filtereinrichtung (92) gekoppelt ist, um eine geradzahlige Mehrzahl der Summen zu summieren, wobei diese Mehrzahl von Summen Bildpunkten zugeordnet ist, die in der den unter Prüfung stehenden Bildpunkt enthaltenden Horizontalzeile liegen, und Bildpunkten, die in einer horizontalen Bildzeile liegen, welche der den unter Prüfung stehenden Bildpunkt enthaltenden horizontalen Bildzeile folgt, wobei die zweite zusätzliche Einrichtung (96, 114, 120) abwechselnde Summen entlang einer horizontalen Bildzeile in entgegengesetzter Polarität miteinander summiert und wobei eine Hälfte der Mehrzahl von Summen in einem positiven Polaritätssinn und eine Hälfte der Mehrzahl von Summen in einem negativen Polaritätssinn addiert werden;
       einen zweiten zusätzlichen Schwellendetektor (100), der mit der zweiten zusätzlichen Einrichtung (96, 114, 120) gekoppelt ist, um ein bewegungsanzeigendes Signal immer dann zu erzeugen, wenn summierte Signale, die von der zweiten zusätzlichen Einrichtung geliefert werden, einen vorbestimmten Betrag überschreiten;
       eine Einrichtung (102), die mit dem ersten und mit dem zweiten zusätzlichen Schwellendetektor gekoppelt ist, um ein Bewegung in der Farbart anzeigendes Signal immer dann zu erzeugen, wenn der erste und der zweite zusätzliche Schwellendetektor gleichzeitig bewegungsanzeigende Signale liefern.
     
    7. Detektor nach Anspruch 6, der ferner eine Einrichtung (16) enthält, die auf das eine Bewegung in der Farbart anzeigende Signal und auf das von der zweiten Ausgangsklemme gelieferte bewegungsanzeigende Signal anspricht, um ein bewegungsanzeigendes Signal zu liefern, wenn das eine Farbartbewegung anzeigende Signal oder das an der zweiten Ausgangsklemme gelieferte bewegungsanzeigende Signal erscheint.
     
    8. Detektor nach Anspruch 6 oder 7, wobei die Summen in Form von Datenabtastwerten erscheinen und die erste zusätzliche Einrichtung (94) folgendes enthält:
       eine mit dem Filter (92) gekoppelte Kaskadenschaltung aus einem ersten und einem zweiten Verzögerungselement (110, 112) zur Lieferung verzögerter Nachbildungen der besagten Summen, wobei jedes der ersten und zweiten Verzögerungselemente die gleiche Verzögerung entsprechend einer ganzen Zahl von Abtastperioden bringt;
       eine Einrichtung (114), die mit dem Filter (92) und mit dem zweiten Verzögerungselement (112) gekoppelt ist, um die Summen-Abtastwerte vom Filter und zweimal verzögerte Summen-Abtastwerte vom zweiten Verzögerungselement in entgegengesetztem Polaritätssinn mit einmal verzögerten Summen-Abtastwerten vom ersten Verzögerungselement (110) zu summieren und damit horizontal-summierte Summen-Abtastwerte zu erzeugen;
       eine weitere Verzögerungseinrichtung (118), die mit der Einrichtung (114) zur Erzeugung horizontal-summierter Summen-Abtastwerte gekoppelt ist und Abtastwertverzögerungen entsprechend einer Horizontalbildzeilenperiode bringt, und
       eine weitere Einrichtung (122), die mit einem Eingang und einem Ausgang der weiteren Verzögerungseinrichtung (118) gekoppelt ist, um die horizontal-summierten Summen-Abtastwerte in entgegengesetzter Polarität zu summieren.
     
    9. Detektor nach einem der Ansprüche 6 bis 8, worin die besagte vorangehende horizontale Bildzeile so ausgewählt ist, daß darin enthaltene Farbartkomponenten in Gegenphase zu Farbartkomponenten sind, die derjenigen horizontalen Bildzeile entsprechen, welche den unter Prüfung stehenden Bildpunkt enthält.
     
    10. Detektor nach Anspruch 1 zur Erfassung einer Bild-zu-Bild-Bewegung in einem Signalgemisch, wobei die Eingangsklemme zum Empfang des Videosignalgemischs (CV) vorgesehen ist,
       die differenzbildende Einrichtung (20, 24) die Differenzen als Abtastwerte von Bild-zu-Bild-Differenzen zwischen einander entsprechenden Signalen aus zwei Bildperioden unter Verwendung derjenigen Frequenzkomponenten des Videosignalgemischs bildet, die Leuchtdichteinformation feiner Bilddetails enthalten,
       und die das Bewegungssignal erzeugende Einrichtung (32, 36, 38) mit der ersten und der zweiten Kombiniereinrichtung gekoppelt ist, um ein Leuchtdichtefeindetail-Bewegungssignal immer dann zu erzeugen, wenn die ersten und die zweiten summierten Differenz-Abtastwerte gleichzeitig einen vorbestimmten Betragswert überschreiten.
     
    11. Detektor nach Anspruch 10, ferner aufweisend:
       eine Einrichtung (20, 22), die mit der Eingangsklemme gekoppelt ist, um Abtastwerte von Bild-zu-Bild-Differenzen aus Frequenzkomponenten des Videosignalgemischs zu erzeugen, die Bildinformation grober Leuchtdichtedetails darstellen;
       eine dritte Einrichtung (26) zur Summierung einer Vielzahl von Differenz-Abtastwerten, welche Information grober Leuchtdichtedetails darstellen, um dritte summierte Differenz-Abtastwerte zu erzeugen, wobei die Vielzahl von Differenz-Abtastwerten, welche Information grober Leuchtdichtedetails darstellen, Bildpunkten entsprechen, die nahe dem unter Prüfung stehenden Bildpunkt liegen, und
       eine mit der dritten Einrichtung gekoppelte Einrichtung (28) zur Erzeugung eines Leuchtdichtegrobdetail-Bewegungsanzeigesignals immer dann, wenn die dritten summierten Differenz-Abtastwerte einen vorbestimmten Betrag überschreiten.
     
    12. Detektor nach Anspruch 11, der ferner eine auf das Leuchtdichtefeindetail-Bewegungsanzeigesignal und auf das Leuchtdichtegrobdetail-Bewegungsanzeigesignal anspricht, um ein Leuchtdichtebewegungs-Anzeigesignal immer dann zu entwickeln, wenn entweder das Leuchtdichtefeindetail- oder das Leuchtdichtegrobdetail-Bewegungsanzeigesignal eine Bewegung anzeigt.
     
    13. Detektor nach einem der Ansprüche 10 bis 12, ferner aufweisend:
       eine mit der Eingangsklemme gekoppelte Einrichtung (90, 92) zur Erzeugung von Bild-zu-Bild-Abtastwertsummen einander entsprechender Signale aus zwei Bildperioden unter Verwendung von Frequenzkomponenten des Videosignalgemischs, die Farbartkomponenten praktisch unter Ausschluß anderer Frequenzkomponenten des Videosignalgemischs enthalten;
       eine mit der Einrichtung zur Erzeugung der Abtastwertsummen gekoppelte erste Einrichtung (94) zum Kombinieren einer Mehrzahl von Abtastwertsummen, die aus Abtastwertsummen ausgewählt sind, welche Bildpunkten entsprechen, die in der den unter Prüfung stehenden Bildpunkt enthaltenden horizontalen Bildzeile und in einer vorangehenden horizontalen Bildzeile liegen, wobei abwechselnde Abtastwertsummen aus einer horizontalen Bildzeile in entgegengesetztem Polaritätssinn kombiniert werden und eine Hälfte der Mehrzahl von Abtastwertsummen in einem positiven Polaritätssinn kombiniert wird und eine Hälfte in einem negativen Polaritätssinn kombiniert wird, um erste kombinierte Abtastwertsummen zu erzeugen;
       eine zweite Einrichtung (96), die mit der Einrichtung zur Erzeugung von Abtastwertsummen gekoppelt ist, um eine Vielzahl von Abtastwertsummen zu kombinieren, die aus Abtastwertsummen ausgewählt sind, welche Bildpunkten entsprechen, die in der den unter Prüfung stehenden Bildpunkt enthaltenden horizontalen Bildzeile und in einer nachfolgenden horizontalen Bildzeile liegen, wobei abwechselnde Abtastwertsummen aus einer horizontalen Bildzeile in entgegengesetztem Polaritätssinn kombiniert werden und eine Hälfte der Mehrzahl von Abtastwertsummen in einem positiven Polaritätssinn und eine Hälfte in einem negativen Polaritätssinn kombiniert werden, um zweite kombinierte Abtastwertsummen zu erzeugen, und
       eine mit der ersten und der zweiten Einrichtung zum Kombinieren von Abtastwertsummen gekoppelte Einrichtung (98, 100, 102) zur Erzeugung eines Farbart-Bewegungsanzeigesignals immer dann, wenn die ersten und die zweiten kombinierten Abtastwertsummen gleichzeitig einen vorbestimmten Betrag überschreiten.
     
    14. Detektor nach Anspruch 13, ferner enthaltend eine Einrichtung (16), die auf das Farbart-Bewegungsanzeigesignal und auf das Leuchtdichtefeindetail-Bewegungssignal anspricht, um ein Bildbewegungs-Anzeigesignal immer dann zu erzeugen, wenn entweder das Farbart- oder das Leuchtdichte-Bewegungsanzeigesignal Bewegung anzeigt.
     




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